Maryland's weather is generally moderate. During the winter it ranges from moderate in the east and south to very cold in the western mountains. Duration of the freeze-free period averages 185 days, ranging from 130 days in Garrett County to 230 days in southern Maryland and the lower Eastern Shore.
Rain. Average annual rainfall: 40.76 inches. Peaks in July and August when thunderstorms average once every five days.
Snow. Average seasonal snowfall: 20.6 inches. Ranges from 10 inches on the lower Eastern Shore to 110 inches in Garrett County.
Temperature. Average annual temperature: 55.1 degrees Fahrenheit. High temperatures occur in July, the warmest month, averaging in the mid to upper 80s. Low temperatures in January, the coldest month, average in the low to mid 20s.
Average monthly temperatures in winter generally are above freezing, and snow remains on the ground usually for only a few days. Minimum daily temperatures do fall below freezing, however, typically more than 80 times a year. The Allegheny Mts. region in the NW, average monthly temperatures during winter are below freezing, average annual snowfall is more than 1520 mm (more than 60 in), and snow stays on the ground for longer periods.